1. Field of Invention
The inventive subject matter relates to implantable medical devices with antimicrobial properties. The antimicrobial characteristics are afforded by inclusion of galvanically releasable material, possessing antimicrobial properties, and inducement of a static electrical charge.
2. Background Art
Materials are selected for inclusion into tissue implantable devices based on necessary strength, flexibility or rigidity, stability over time and their reactivity to tissue and physiological fluids. It is highly desirable to employ materials that evoke a minimal tissue response. Materials that have been found useful in endoprosthetic applications include cobalt chromium and molybdenum alloys and titanium and titanium alloys. Other, non-metallic materials have also been utilized, such as ceramic and carbon-based materials, as well as synthetic plastic, with some success. In all of these materials, an important characteristic is for the material not to be bioreactive (i.e., bioinert), durable and, in many cases, strong.
Another important consideration in implant surgery is infection control. The increased use of surgical implants, particularly in patients with compromised or reduced immune responses, makes control of infections in these patients a high priority (Darouiche, Clin. Infect. Dis., 33: 1567-72 (2001)). Infections associated with surgical implants are generally cumbersome to manage, have a significant impact of the quality of life of the patient and often result in prolonged hospital stays (Boxma, et al., Lancet, 347: 1133-1137 (1996); Whitehouse, et al., Infect. Control Hosp. Epidemiol., 23: 183-189 (2002)). Multiple approaches to controlling infection due to implants exist, including: irrigation of the surgical field; placement of an antimicrobial carrier near the wound site. However, more effective approaches at controlling infection following insertion of implants are desirable.